+1 for whirlpool.
If you want cheap internets and don't want to get anal raped, best do some research first. If you see an ISP/plan you like go on the whirlpool forums and see what other people say about them.
There isn't one plan that will suit everybody, obviously. I work for Bigpond and I'm probably the last person to recommend them, as they are hells expensive, unless you can get cable. But if you have a Telstra homephone their offers can be quite attractive (with a contract though.)
Basically you get what you pay for, and no matter what anyone says, customer service is important. Oh and some ISP's have a connection fee, so watch out for that.